The present invention relates to a waterproof structure for a wire part and a method of manufacturing the structure. In detail, it relates to a waterproof structure for waterproofing a wire leading part in a wiring instrument (e.g. a Waterproof connector, an electrical connection box etc.) by a rubbery elastic member and a method of manufacturing the waterproof structure.
For example, Japanese Unexamined Utility Model Publication (Kokai) No. 50-54591 discloses a conventional art waterproof structure where a plurality of covered wires are interposed between an upper half rubber plug and a lower half rubber plug, so that the resulting plug assembly is press-fitted into a recess formed on a connector housing.
In the above-mentioned conventional waterproof structure, however, there are problems to be solved despite that the plural wires can be waterproofed collectively. That is, it is troublesome for a worker to fit the rubber plug assembly into the connector housing and the manufacturing cost is increased due to the necessity of establishing different molding dies for the upper and lower rubber plugs in accordance with the size of wires and the number of poles.
In addition, Japanese Unexamined Utility Model Publication (Kokai) No. 5-57772 discloses another conventional waterproof structure where a pair of packing holders are slidably attached to a connector housing, so that a pair of packings can be pressed against wires from the upper and bottom sides by manipulating the packing holders.
Although this waterproof structure facilitates a sealing operation with the packings relatively and copes with the differences in sizes of wires and numbers of poles to a certain extent, it is unavoidable that a clearance between the pair of packings is produced by the side of the wire. Therefore, the above structure has a disadvantage of lowered waterproof performance.